Clad-pumped bismuth fibre laser emitting in the wavelength range from 1.3 to 1.4 μm

A bismuth-doped fibre laser operating in the spectral region 1.3 – 1.4 μm and pumped into the cladding of an active fibre by multimode semiconductor diodes at a wavelength of 0.79 μm has been fabricated for the first time. Experimental data are presented on the operation regimes of various configurations of the laser, obtained by changing the reflection coefficients and spectral selectivity of the mirrors, as well as the length of the active fibre. The slope efficiency of the bismuth-doped laser at a wavelength of 1360 nm is 1.4% with respect to the pump power launched into the fibre cladding, and the maximum output power exceeds 300 mW.